/in/foo.cc: In function 'int main()':
/in/foo.cc:9:13: error: 'long' invalid for 'x'
  long float x=0,k=0;
             ^
/in/foo.cc:9:17: error: 'long' invalid for 'k'
  long float x=0,k=0;
                 ^
/in/foo.cc:10:13: error: 'long' invalid for 't'
  long float t=0;
             ^
/in/foo.cc:11:7: warning: unused variable 'flag' [-Wunused-variable]
  bool flag=false;
       ^~~~